With Stephon Tuitt’s announcement that he will be bypassing his senior season with the Irish - coupled with the decision by nose guard Louis Nix to leave for the NFL after four years in the program - the front wall that led Notre Dame to the No. 2 scoring defense, No. 7 total defense and No. 11 rushing defense in 2012 is officially deconstructed.

“Thanks for a wonderful three years at the best University on earth. I will forever be IRISH,” Tuitt posted on Twitter Sunday.

The reconstruction of Notre Dame’s defensive line begins now, and for the younger players in the program, opportunity is knocking at an ear-splitting decibel level.

Nix and Tuitt joined fifth-year senior Kapron Lewis-Moore in ’12 to form one of the most dominant defensive fronts in Notre Dame history with Sheldon Day, Tony Springmann and Kona Schwenke adding valuable minutes off the bench.

In 2013, Day stepped into the starting lineup for the departed Lewis-Moore, but Springmann was lost for the season with a torn ACL. That forced young players such as Isaac Rochell and Jarron Jones into the lineup more frequently than anticipated, particularly when Tuitt struggled out of the gate with his conditioning following off-season hernia surgery and Nix suffered a late-season knee injury.

Now Nix, Tuitt and Schwenke are gone, and the future of Notre Dame’s defensive line is a scrambled puzzle with nary an interlocking part.

Day is the foundation of the newly-constructed front. Sophomore-to-be Isaac Rochell, who saw action in 12 games and made 10 tackles, figures to be a frontrunner for a starting defensive end position. Junior Jarron Jones, who emerged as a legitimate interior defensive lineman when Nix and Schwenke went down with injuries, is at the forefront of Notre Dame’s future plans in the middle.

New defensive coordinator Brian VanGorder and Irish defensive line coach Mike Elston have a thousand reps to oversee and some long hours of analysis beyond those three. VanGorder presumably will stick with his 3-4 base defense, which head coach Brian Kelly prefers against today’s wide-open, sideline-to-sideline attacks.

Springmann’s injury, which included a setback due to an infection, has him on a longer road to recovery, although by fall, the 6-foot-6, 296-pounder should be a nose guard/end option once again.

The Irish remain hopeful that senior-to-be Chase Hounshell, an undersized end prospect who has missed the last two seasons with a shoulder injury, can return to the field and at least provide the Irish with some backup snaps.

Another option could be fifth-year candidate Justin Utupo, an undersized yet fairly stout defensive lineman who came in handy in the second half of the 2013 season. Sophomore-to-be Jacob Matuska preserved a year of eligibility in 2013 and will be in the mix. Undersized senior-to-be Anthony Rabasa has bounced between linebacker and end.

Cat linebackers Ishaq Williams and Romeo Okwara will factor into the mix with a hand on the ground, particularly when the Irish go with four down, although Williams becomes a viable option at end in the 3-4 with Tuitt’s departure. Switching Williams to a full-time end might be the first order of business now that it’s official with Tuitt.

Notre Dame could use a freshman or two to make a dent on the depth chart in ’14. Andrew Trumbetti, Jonathan Bonner, Jay Hayes and Matt Dickerson join the fold, giving the Irish some much-needed numbers if not experience. If Ishaq Williams makes the move to end, freshmen Grant Blankenship - projected long-term as an end - Jhonathon Williams and Kolin Hill become instant Cat linebacker candidates.

The stout defensive front that helped carry the Irish to the national title game in ’12 officially is gone. Let the reconstruction begin.